Self-propelled and self-levelling open trench caisson



Se t. 7, 1965 'r. B. HILL, JR., ETAL 3,204,415

SELF-PROPELLED AND SELF-LEVELLING OPEN TRENCH CAISSON Filed May 51, 19632 Sheets-Sheet 1 THOMAS B. HILL, JR. BRUCE E. SMITH ATTORNFY w INVENTOR.

United States Patent 3,204,415 SELF-PROPELLED AND SELF-LEVELLING OPENTRENCH CAISSQN Thomas I5. Hill, Jr., 920 Leslie SE., and Bruce E. Smith,

750 Summer SE., both of Salem, Oreg. Filed May 31, 1963, Ser. No.284,543 3 Claims. (Cl. 61-41) This invention is concerned with thelaying of pipes, conduits and the like, particularly large pipes such asconcrete sewer pipes, in trenches of substantial depth, where thetrenches have approximately vertical walls and are restricted as towidth.

As is well known, when work of this nature is performed in trenches ofany appreciable depth, it is customary and necessary to prevent possiblecaving in of the earth walls by providing means for temporarily shoringup the walls in order to protect workmen in the trench and also toprevent damage to extending surface areas adjacent the trench when thetrench, for example, is located along a busy street or paved roadway.The common practice of temporarily shoring up the side Walls of trenchesby timbers and other support elements requires a considerableexpenditure of time and labor, and the danger of having thisprecautionary work done inadequately or too carelessly is wellrecognized.

An object of the present invention is to provide a prac tical and mobiledevice which will dispense with the necessity of any temporary shoringup of the trench walls where the device is positioned and which caneasily be set up and installed in a trench where desired and moved alongas the pipe-laying operation in the trench progresses.

Another object is to provide a special open end trench caisson, openalso at top and bottom, which, when installed in a trench where a pipeline is being laid, will be capable of propelling itself forwardly alongthe trench as the trench is dug and as the pipe sections are set inplace in the pipe line.

With the customary digging of deep trenches for pipe lines the bottom ofthe trench will generally be left uneven or with minor depth variations,inasmuch as the additional cost in time and labor of making the bottomof the trench smooth and level throughout and without variations indepth would not be justified. A further important object of the presentinvention accordingly is to provide an improved trench caisson for pipelaying which will be self-levelling in addition to being self-propellingas the caisson moves along with the laying of the pipe line in thetrench.

A related object is to provide an open caisson for trench work in whichboth the self-propelling means and the selflevelling means will beoperated through simple and practical mechanism adapted for easy controlby a single operator.

Since trenches in which pipe lines are laid are of various widths,depending upon the size of the pipe in the trench, and since it is notdesirable to have such trenches wider than suitable for the work inhand, an additional object of thisinvention is to provide an improvedtrench caisson which can readily be adjusted in width to accommodatetrenches of dilferent size.

The means by which these objects and incidental advantages are attainedwith the device of the present invention, and the'construction andmanner of operation of this open trench caisson, will be brieflyexplained and described with reference to the accompanying drawings.

In the drawings:

FIG. 1 is a sectional elevation taken on line 11 of FIG. 2;

FIG. 2 is a plan section taken on line 22 of FIG. 1;

3,204,415 Patented Sept. 7, 1965 "ice FIG. 3 is a transverse sectionalelevation taken on line 33 of FIG. 1 but drawn to a slightly largerscale;

FIG. 4 is a fragmentary section taken on the off-set line indicated at44 in FIG. 1, drawn to the same scale as FIG. 3; and

FIG. 5 is a diagram illustrating the hydraulic means by which the deviceis operated and controlled.

Referring to FIGS. 1, 2 and 3, the device includes a pair of compositeside Wall structures each having a rigid frame formed of vertical andhorizontal frame members which are welded together at their junctionsand having wall plates welded to the outside face of the frame. Thus thetwo Wall structures include bottom longitudinally-extending frame member10, 10' respectively, top longitudinally-extending frame members 11, 11respectively, inner vertical frame members 12, 12', all of which memberspreferably, although not necessarily, are tubular and square in crosssection, forward vertical frame members 13, 13 respectively, shown inthe drawings as I- beams, horizontal ribs or I-beam frame members 14,14', and outside wall plates 15, 15'.

In addition, each side wall structure has a forwardlyextendingtriangularly shaped, bottom portion comprising a substantiallyhorizontal bottom frame member (one of these being shown at 23 in FIGS.1 and 4), a down- Wardly-forwardly sloping top frame member indicated at24, 24 respectively (FIG. 2), and a side wall plate, one of which isshown at 25 in FIG. 1.

The two composite side wall structures are adjustably connected by pairsof telescoping cross tubular members 16 and 16', 17 and 17', 18 and 18',19 and 19, 20 and 20, and 21 and 21', which are mounted in the locationsshown in FIG. 1. The pairs of telescoping members are provided Withholes to receive securing bolts (as indicated at 22 in FIG. 2) forsecuring each pair of telescoping members rigidly together so as to holdthe two wall structures firmly in parallel spaced position, spaced apartin accordance with the overall width desired for the device, which widthwill of course depend upon the width of the particular trench T in whichthe device is to be set to operate. The fact that the overall width ofthe device may be adjusted as desired is one of the important featuresThe junctions of the upper pairs of telescoping cross members 16, 16 and17, 17' with the repective wall structures are reinforced by gussets 26,26 and 27, 27' respectively to give greater overall rigidity to thedevice. The forwardly extending bottom portions of the wall structuresand the foremost telescoping cross members 21, 21' constitute a forwardfoot extension for the caisson.

A pair of shoe runners 28, 28' (FIGS.1, 2, and 4) are mounted in theforward foot extension of the caisson. These shoe runners are connectedby hinge links 29, 29' respectively to the foremost pair of telescopingcross members 21, 21' respectively. The shoe runners 28, 28' and theirhinge links 29, 29' are also hingedly connected to the lower ends ofpiston rods 30, 30' respectively of pistons located in double-actinghydraulic cylinders. One of these hydraulic cylinders is shown at 31 inFIG. 1 and while only one of these cylinders and mounting connectionsare shown in the drawings it is to be understood that both shoe runners28, 28' are identically mounted and connected with the piston rods oftheir respective hydraulic cylinders. The upper ends of these two hydraulic cylinders are hingedly supported from a pair of innerdownwardly-forwardly sloping frame members 32, 32' respectively, whichframe members 32, 32 extend from the telescoping cross members 19, 19'respectively, to the foremost telescoping cross members 21, 21'respectively.

The device is supported at the front end on the shoe runners 28, 28, andthe independent operation of the pair of hydraulic cylinders 31, aslater mentioned, enables the front end of the device to be raised -orlowered with respect to the bottom of the trench at either side.

A pair of double-acting hydraulic cylinders 33 and 33' (FIGS. 1 and 3)are mounted in horizontal position in the side wall structuresrespectively in the approximate location indicated in FIG. 1. Pistonrods 34, 34 extend forwardly from the cylinders 33, 33 respectively andpass slidably through the respective vertical frame members 12, 12. Atransversely-extending thrust bar 35 has its ends removably mounted intracks provided by pairs of horizontal I-beams in each side wallstructure respectively. The ends of the thrust bar are attached to theends of the piston rods 34, 34 respectively. Thus the operation of thehydraulic cylinders 33, 33 in unison enables the thrust bar 35 to movefrom the forward position, shown in FIG. 2, to the rear position, shownin FIG. 1, and back again to the normal forward position.

Briefly the operation of the device as thus far described is as follows:The device, adjusted to the proper width for the size of the trench andwith the proper length thrust bar set in place and attached to thepiston rods 34, 34', is set down into the trench over the pipe line withthe end of the pipe line already laid extending approximately halfwayalong the device and thus terminating in the position shown by the lastpipe section P in FIG. 1. The thrust bar 35 is moved to the left (asviewed in FIG. 1) into the normal position shown in FIG. 2. Anadditional pipe section P (FIG. 2) is then lowered down into the deviceand trench by suitable means (not shown) until the new pipe section isin proper axial alignment with the previously laid portion P of the pipeline. Gravel or other suitable material is dumped into the trench toenable the space beneath the new pipe section P to be filled andcompacted for properly supporting the new pipe section, and :thelowering and temporary supporting means for the new pipe section is thenwithdrawn. The hydraulic cylinders 33, 33' are operated to cause thethrust bar 35 to move against the forward end of the new pipe section inthe direction indicated by the arrow X in FIG. 2. With the cement orother sealing material having been applied to the end of the previouslylaid pipe portion P for the sealing of the new joint to be formed, thenew pipe section P is shoved into closed position with the previouslylaid pipe section P. Then as the movement of the thrust bar continuesrelatively rearwardly with respect to the caisson the entire device ismoved forwardly in the direction indicated by the arrow Y in FIG. 2 fora distance equal to the length of the added pipe section. The operationis then repeated for the next pipe section.

As previously mentioned, the front end of the caisson is supported onthe pair of shoe runners 28, 28, and, as the device is shoved forwardlyalong the trench with each relatively rearward movement of the thrustbar, the two shoe runners slide along on the bottom of the trench, andthe raising or lowering of the shoe runners enables the caisson to bemaintained at the desired level regardless of irregularities along thebottom of the trench as the trench is dug. This is another importantfeature of the invention.

Preferably the filling of the trench on top of the laid pipe line takesplace at the immediate rear of the caisson as it moves along. Also thedigging of the trench can take place a short distance ahead of thetraveling caisson.

Thus with such procedure only a minimum portion of the trench will everbe entirely open with its side Walls unprotected against cave-in.

The forward-extending foot portion of the device, formed by thetriangular side wall extensions and the foremost pair of bottomtelescoping cross members 21, 21, carries a pair of overlapping topplates 48, 48 which are secured at their outer edges to the twodownwardlyforwardly sloping top members 24, 24 of the opposite sidewalls respectively. The purpose of these sloping top plates is toprevent any excessive amount of earth or gravel, from the bottom of thetrench in front of the moving caisson, from passing into the caisson andinterfering with the positioning of a new pipe section as a new pipesection is let down into the caisson and trench, since the accumulationof such material at this location within the caisson prior to thelowering of the new pipe section would necessitate removal of suchmaterial by hand and thus slow down the pipe laying operation.

Preferably the two forward vertical I-beams 13, 13 are provided withpairs of sockets for supporting a pair of cross boards 36 and 37 (FIGS.1 and 3) which serve also to prevent undesirable earth and gravel frompassing into the interior of the front portion of the caisson.

For use with extra deep trenches the caisson is provided with auxiliaryremovable top board extensions 38, 39, 40 and 41 for each of the sidewall structures, as indicated in FIGv 1, suitable sockets being providedon the top longitudinal frame members 11, 11 for the pairs of extensionboards 38 and 39, and these boards in turn carry sockets for the nextupper boards 40 and 41. Obviously other means for mounting removable topextensions on the side wall structures might be employed.

The operating power plant for the device is carried on a platform 42mounted on the top of the caisson at the rear, as shown in FIGS. 1 and2. The power plant is a simple one including either an electric motor orinternal combustion engine 49 for operating a hydraulic pump. The powerplant is equipped with suitable valves which are easily and convenientlymanipulated by the operator stationed on the platform 42 who thus isable to control the entire operation of the caisson. Referring brieflyto the diagram in FIG. 5, the operation of the pump 43 with the mastercontrol valve 44 in the position illustrated, enables the hydraulicfluid from reservoir 47 to be delivered under pressure into either endof the cylinders 33, 33, as desired, through the valves 45, 45respectively, for operation of the thrust bar. Ordinarily the two valves45, 45' will be open and closed in unison, but, in the event the pistonin either of the cylinders 33, 33 moves slightly faster than the otherpiston, this can be corrected by adjustment of these individual valves.Similarly the manipulation of valve 46 and valve 46 enables thecorresponding hydraulic cylinders for the shoe runners 28 and 28 to beoperated when raising or lowering of the front end of the caisson ateither side with respect to the bottom of the trench is required.

It would be possible to have various minor modifications in thestructure herein illustrated and described without departing from theprinciple of the invention, and while the device in the form describedhas proved very satisfactory in operation and such structure is regardedas the preferred means for the carrying-out of this invention, it is notdesired to limit the invention otherwise than as provided in the claims.

We claim:

1. A self-propelled and self-levelling caisson for an open pipelinetrench including a pair of reinforced side walls, cross bars adjustablysecuring said walls in parallel vertical planes spaced apart a distancecorresponding approximately to the width of the trench, a pair ofhydraulic cylinder assemblies mounted on the inside of said side Wallsrespectively, a transversely extending movable thrust bar, guide waysfor the ends of the thrust bar in said side walls respectively andlocated in the same horizontal plane with said hydraulic cylinderassemblies, the ends of said thrust bar slidable in said guide ways andconnected with the piston rods of said cylinder assemblies respectively,said cylinder assemblies and said thrust bar positioned at such heightabove the bottom of said side Walls that said thrust bar will extendacross the end of the pipeline in the trench within the caisson whensaid caisson is positioned in the trench, whereby the forcible movementof said thrust bar against the end of each pipe section as such sectionis added to the pipeline within said caisson will cause said caisson tobe moved forwardly in the trench, a pair of shoe runners supporting theforward end of said caisson and adapted to slide along on the bottom ofthe trench, adjustable flexible mounting means on said caisson for saidshoe runners, said mounting means including hydraulic cylinders forraising or lowering each shoe runner independently, and a power plant onsaid caisson with controls for said first mentioned cylinder assembliesand for said last mentioned hydraulic cylinders.

2. A self-propelled and self-levelling caisson for an open pipelinetrench including a pair of reinforced main side Walls, cross barsadjustably securing said walls in parallel vertical planes spaced aparta distance corresponding approximately to the Width of the trench, apair of hydraulic cylinder assemblies mounted on the inside of said sidewalls respectively, a tranversely extending movable thrust bar, guideWays for the ends of the said thrust bar in said side walls respectivelylocated in the same horizontal plane with said hydraulic cylinderassemblies, the ends of said thrust bar slidable in said guide Ways andconnected with the piston rods of said cylinder assemblies respectively,said cylinder assemblies and said thrust bar positioned at such heightabove the bottom of said side walls that said thrust bar will extendacross the end of the pipeline in the trench within the caisson whensaid caisson is positioned in the trench, whereby the forcible movementof said thrust bar against the end of each new pipe section as suchsection is added to the pipeline within said caisson will cause saidcaisson to be moved forward ly in the trench, a rigid foot extension onthe forward end of said caisson extending forwardly in the direction oftravel of said caisson, said foot extension includingtriangularly-sha-ped reinforced side wall extensions having their bottomedges in alignment with the bottom edges of said main side walls, anadjustable cross bar connecting the tip ends of said side wallextensions, an adjustable cover plate assembly mounted on said footextension, a pair of shoe runners supporting the forward end of saidcaisson and adapted to slide along on the bottom of the trench,adjustable flexible mounting means on said caisson for said shoerunners, said mounting means including hydraulic cylinders for raisingor lowering each shoe runner independently, and a power plant on saidcaisson with controls for said first mentioned cylinder assemblies andfor said last mentioned hydraulic cylinders.

3. A self-propelled and self-levelling caisson for an open pipe trenchconsisting of a pair of reinforced main side walls, cross barsadjustably securing said walls in parallel vertical planes spaced aparta distance corresponding approximately to the width of the trench, apair of hydraulic cylinder assemblies mounted on the inside of said sidewalls respectively, a transversely extending movable thrust bar, guideways for the ends of said thrust bar in said side Walls respectivelylocated in the same horizontal plane with said hydraulic cylinderassemblies, the ends of said thrust bar slidable in said guide ways andconnected with the piston rods of said cylinder assemblies respectively,said cylinder assemblies and said thrust bar positioned at such heightabove the bottom of said side walls that said thrust bar will extendacross the end of the pipeline in the trench within the caisson whensaid caisson is positioned in the trench, whereby the forcible movementof said thrust bar against the end of each new pipe section as suchsection is added to the pipeline within the caisson will cause thecaisson to be moved forwardly in the trench, a rigid foot extension onthe forward end of said caisson extending forwardly in the direction oftravel of said caisson, said foot extension includingtriangularly-shaped reinforced side wall extensions having their bottomedges in alignment with the bottom edges of said main side walls, anadjustable cross bar connecting the tip ends of said side wallextensions, an adjustable cover plate assembly mounted on said footextension, a pair of shoe runners supporting the forward end of saidcaisson and adapted to slide along on the bottom of the trench,adjustable flexible mounting means within said foot extension on saidcaisson for said shoe runners, said mounting means including linksconnecting said shoe runners to said last mentioned cross bar and a pairof hydraulic cylinders mounted in said foot extension and connected withsaid shoe runners respectively for positioning each shoe runnerindependently, and a power plant on said caisson with controls for saidfirst mentioned cylinder assemblies and for said last mentionedhydraulic cylinders.

References Cited by the Examiner UNITED STATES PATENTS 1,63 8,343 8/27Knudsen 6141 1,817,367 8/31 Greiman 6l41 2,908,140 10/59 Everson 61-412,997,853 8/61 Kemper 6l-85 3,089,310 5/63 Torti 6141 OTHER REFERENCESEngineering-News-Record Magazine, Sept. 15, 1955, pp. 4041 (copy inGroup 420).

CHARLES E. OCONNELL, Primary Examiner. EARL I. WITMER, Examiner.

1. A SELF-PROPELLED AND SELF-LEVELLING CAISSON FOR AN OPEN PIPELINETRENCH INCLUDING A PAIR OF REINFORCED SIDE WALLS, CROSS BARS ADJUSTABLYSECURING SAID WALLS IN PARALLEL VERTICAL PLANES SPACED APART A DISTANCECORRESPONDING APPROXIMATELY TO THE WIDTH OF THE TRENCH, A PAIR OFHYDRAULIC CYLINDER ASSEMBLIES MOUNTED ON THE INSIDE OF SAID SIDE WALLSRESPECTIVELY, A TRANSVERSELY EXTENDING MOVABLE THRUST BAR, GUIDE WAYSFOR THE ENDS OF THE THRUST BAR IN SAID SIDE WALLS RESPECTIVELY ANDLOCATED IN THE SAME HORIZONTAL PLANE WITH SAID HYDRAULIC CYLINDERASSEMBLIES, THE ENDS OF SID THRUST BAR SLIDABLE IN SAID GUIDE WAYS ANDCONNECTED WITH THE PISTON RODS OF SAID CYLINDER ASSEMBLIES RESPECTIVELY,SAID CYLINDER ASSEMBLIES AND SAD THRUST BAR POSITIONED AT SUCH HEIGHTABOVE THE BOTTOM OF SAID SIDE WALLS THAT SAID THRUST BAR WILL EXTENDACROSS THE END OF THE PIPELINE IN THE TRENCH WITHIN THE CAISSON WHENSAID CAISSON IS POSITIONED IN THE TRENCH, WHEREBY THE FORCIBLE MOVEMENTOF SID THRUST BAR AGAINST THE END OF EACH PIPE SECTION AS SUCH SECTIONIS ADDED TO THE PIPELINE WITHIN SAID CAISSON WILL CAUSE SAID CAISSON TOBE MOVED FORWARDLY IN THE TRENCH, A PAIR OF SHOE RUNNERS SUPPORTING THEFORWARD END OF SAID CAISSON AND ADAPTED TO SLIDE ALONG ON THE BOTTOM OFTHE TRENCH, ADJUSTABLE FLEXIBLE MOUNTING MEANS ON SAID CAISSON FOR SAIDSHOE RUNNERS, SAID MOUNTING MEANS INCLUDING HYDRAULIC CYLINDERS FORRAISING OR LOWERING ECH SHOE RUNNER INDEPENDENTLY, AND A POWER PLANT ONSAID CAISSON WITH CONTROLS FOR SAID FIRST MENTIONED CYLINDER ASSEMBLIESAND FOR SAID LAST MENTIONED HYDRAULIC CYLINDERS.